Improvement in purchases for capstans



tniih I iaia 4Josera EDeEcoMB, or cantinas, MAINE.

'Letters Patent No. 113,032, dated March 2'8, 1871.

iMPROVEMENT IN PURCHASES FOR CAPSTANS.

The Schedule referred to in these Letters Patent and making part of the same.

To all 'whom it may concern:

Be it known that I, JOSEPH Eveneens, of Gardiner, in the county of Kennebec and State of Maine, have invented a new and useful Improvement in Purchase for Oapstans and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable othets to make and use my invention, reference being had to the accompanying ,drawing forming part of this specification, in which` Figure l is a top plan of my invention, with a part broken out to show the pawls and slide.

Figure 2 is a top plan, with half of the exterior removed tov show the full interior.

Figure 3 is a section, to show the method of reducing the friction ofthe gear.

My invention relates to y'improvements in the common form of purchase for capstans.

The shell is composed of halves, concave on the interior, to hold the gear, pawls, Src., and then'holted together.

The hole in the purchase receives the end of the capstan, and has the ribs a to fitgrooves in the same, so as to communicate the motion of the pui'- chase or lever t0 the capstan.

The general operation is: g

As the purchase or lever b is turned part of the way around, the pawls o, striking the teeth of the gear d, move it, and with it thecapstan.

The lever b is then turned -back,'the pawls slipping back over the teeth of the gear, and so the operation of turning the capstan continued till the cable is wound up.

This operation I do 'not claim.

My' invention has special reference to'a method of throwing the pawls o out of the teeth oi' the gear d, and then holding them as long as may be desired. For effecting this, very imperfect devices have hitherto been employed.

I accomplish this by Ilthe slide c, which has, on the inside of one-half of the` casing or casting of the purchase, a groove, iu which to slide or move.

The end oi' the slide. that touches the pawl is inclined, as shown in igs'. -1 andv2. Y

It is kept pressed upagainst the inside of the casing by the spring fon the outside, which presses against the outside of the casing, 1and so keeps the slide with a proper degree of frictiony against the inside of the casing.

This is in order that, when moved to either position, either backward'or forward, it will stay in place, and not move without -being pushed `-by the knob 71 which has a stock extending through the casing and united with the slide e. The spring f also covers a slot in the casing in which the stock moves.

The spring here shown is elliptical; but a hollow knob or projection can he used instead, with a spiral coiled around the 'stock andy resting on the outside of the casing. Some elastic force must, however, be employed, because, if the slide were merely held by friction, it would soon Wear loose and become unre" liable.

.The lower pawl has the arm t', extending towardA the inclined face of the slide e.

When the slide is pushed up, as in iig. 1, its inclined Aend strikes the arm t', throws out the first pawl, and .it the second, and so on through the set.

The pawls are set on pivots, having projections on their pivotal ends which enter sockets prepared for I relieve the friction ofthe gear (l by hollowing out the casing where its lip or shoulder rests, as seen at m, in fig. 3.

I do not claim a lever down through the center or around the sides 'ot' the pawls of the windlass-pur' chase, and a hook-shape oi' the lever, to secure the pawls in their places when they are out of the ratchet, as set out in the case oi' David Thomas, received and filed July 26, 1847. This combination. presents the objections which mine is intended to avoid.

I operate the pawls by a slide moving within the case, aud held in position by a spring when so moved' v as to lift the pawls from the ratchet.

The arm or lever in Thomass combination is apt to slipI oir the edge of the aperture through which it. enters the case,'and so check the ratchet when not desired. This my invention avoids.

What I claim as my invention, and desire to secure by Letters Patent, is.-

In :ai-purchaseA for capstans, the combination of' the spring-slide e and the arm t', attached to one of the pawls, as set forth. x

JOSEPH EDGECOMB.

' Witnesses:

J'osmn Manor, S. BOWMAN. 

